Burden-switching apparatus and method



Oct. 19, 1954 o BROWN BURDEN-SWITCHING APPARATUS AND METHOD 2Sheets-Sheet 1 Filed Nov. 1, 1 946 INVEN TOR.

Oct. 19, 1954 0. BROWN 2,692,121

BURDEN-SWITCHING APPARATUS AND METHOD Filed Nov. 1, 1946 2 Sheets-Sheet2 INVENTOR.

Patented Get. 19, 1954 UNITED STATES PATENT OFFICE BURDEN-SWITCHIN GAPPARATUS AND METHOD Owen Brown, Los Angeles, Calif. ApplicationNovember 1, 1946, Serial No. 707,151 11 Claims. (01. 258 1.8)

This invention relates to transportation-especially to airborne andsurface carriers, including coactive relations therebetween-andcomprises novel means and methods applicable thereto.

More specifically, it introduces improved apparatus for both theso-called pickup and the so-called delivery of burdens-such as mailpouches, canisters, human beings, and articles of sundry other adaptabletypes-from one rapidly traveling body to another by means of both.inboard and outboard tackle components carried by the respectivebodies.

For illustration, it introduces means for switching burdens of variouskinds and sizes from one aircraft to another while in flight. Foranother typical example, it may be employed in a somewhat comparablemanner for transferring such burdens from an airborne craft to arailborne or similar vehicle at relative speeds preferably, but notnecessarily, approximating covelocities therebetween.

Therefore, the invention is to be regarded as a concurrent extension ofthe art disclosed in my co-entered application entitled IntercooperativeSystem for Airborne and Surface Carriers, Serial No. 707,153 of 1946,now Patent No. 2,639,107, wherein I provide entirely new rollabledevices, capable of attaining and of consistently maintaining at leastmoderately high airplane speeds. And since said other named applicationdeals quite fully with means and methods for aerially switching one ormore towable gliders from one locomotive plane to another as well asfrom a locomotive plane to a railborne tow-car and vice versa, thepresent embodiments are explained only with respect to said first-namedgenerality of burdens rather than to glider operations, notwithstandingthat certain of the apparatus features herein may be employed inglider-towing and glider-switching services as well. It is obvious,moreover, that the apparatus and the methods are applicable to stillother fields, including the marine field, as elsewhere mentioned. Seealso my co-entered application entitled Means for Conducting BlitzWarfare, Including Methods Therewith, filed November 1, 1946, as SerialNo. 707,152, now Patent No. 2,634,924.

For some years mail pouches and relatively small parcels have beensuccessfully delivered to and picked up from various ground stations byairborne light planes, having thereon extensible and retractable booms,including pickup hooks, or grapples, of preferred types and othercomplementary snatch-tackle, inclusive of automatic delayed-actionwinches and burden-lines cooperable therewith. Such apparatus is wellknown 2 and need not be further detailed. The same has been limited,however, to operations wherein only one carrier is employed for eachengagement (the earth, as a movable body, not being considered asanother carrier in the meaning and intent of the invention) and whereinsuch one carrier, flying at pickup speeds which may normally exceedmiles per hour, must necessarily make a large daily number of surfacecontacts over each route which is flown. Because, in order to carry onprofitable operations, the pickup planes are of very small inexpensivesizes, having extremely limited individual cargo capacities, theoperations of such a system per se, however widespread and financiallysuccessful it may be, is obviously and necessarily quite circumscribed.

In short, the class of equipment currently em ployed, and the techniquesused therewith, have heretofore excluded its economical application onlong-range, heavy-duty schedules. Moreover, it would be even moreuneconomical to utilize large airliners, of the Constellation class, forexample, in ordinary local pickup and delivery services. But accordingto one embodiment of my invention, both general classes of carriers maybe utilized cooperatively, each entirely within its own sphere ofefficiency, wherein the maximum of profitable pay-load may be carried byeach type of craft in proportion to the miles flown.

Specifically, large transcontinental type planes, flying regularschedules, may, at very low cost, be fitted with equipment designed toreceive large quantities of previously picked-up mail and other freightfrom light planes adapted to make very brief contacts therewith and atnon-stop speeds therebetween, which speeds need be but momentarily less,perhaps, than the regular cruising speeds of the larger craft, asrequired. Much additional mail and light freight other than picked-uploads could also be fed to the transcontinental carriers in this manner(as more fully explained hereafter) from innumerable offcourse points ofinitial consolidation. And for this special service, feeder planes ofany desirable intermediate size could be utilized. Return loads, also,could be handed over non-stop by the big liners to such light planes,for the return flights to said off-route bases. Similarly, railbornevehicles-as hereinafter explainedtraveling extensive lengths oftrackage, could be contacted in like manner by the light pickup and/orfeeder planes, and burdens thereby exchanged back and forth.

However, it is not entirely essential that the respective bodies shallbe traveling at approximate co-velocities since, according to facilitiesherein disclosed, it would be possible for one of the light pickup orthe intermediary feeder planes, for illustration, flying at a speedexceeding 100 miles per hour, to effect pickup and/or delivery contactwith the mail and/or baggage car or cars of an existing type of railroadtrain, the latter traveling at substantially less than 100 miles perhour. Thus the invention may have other uses aside from those brieflyand graphi cally set forth herein, and may be carried out by theemployment of various other means and methods aside from those which arespecifically shown and explained.

It is a primary object of the invention to extend existing aerial pickupand delivery facilities to include the use of many types and sizes ofaircraft. Thus large airborne gliders, as a further illustration, whilein the tow of tow-cars or locomotive planes-as more fully dealt with inmy said first mentioned co-entered applicationcould also be adapted forbaggage switching with aircraft of existing or future types, such as nowor hereafter employed in pickup and delivery duties.

Another object is to provide means whereby a given pickup light planemay cover a predetermined local route according to schedule, and,thereafter, without making any preliminary ground contact, and merelyasdesired-coordinating its time table to that of a relatively longer rangetransport or even a transcontinental airliner, meet said longer rangingplane for pickup and delivery duties prior to making a return flightover the previous or any other predetermined route while still airborne.

Another object, preliminary to the introduction of very-high-speed railcarriers according to my first mentioned co-entered application, is tomake possible aerial contacts between existing types of pickup planesand railborne surface vehicles traveling at present railroad trainspeeds.

In line with the foregoing objects, it is another objective to providespecial types of pickup and delivery facilities, as hereafter dealtwith, wherewith operations can be carried on with the greatest ease, andeconomically, wherewith schedules may be maintained punctually, andwherewith the possibility of mishaps can be reduced to a minimum.

Another object is to fill th serious breech which will, ordinarily, becreated when existing airliners, driven solely by reciprocating engines,are replaced by much faster craft powered by gas turbine motors or suchmotors geared to propeller shaftings, making possible the indefinitefurther use of these outmoded passenger liners in lower speed, so-calledco-velocity services.

Another object, in time of war, is to provide means whereby importantbaggage may be quickly, expeditiously transferred from one plane toanother while airborne; as, for example, for the emergency delivery ofbombs, rockets or other ammunition, first-aid and other medicalsupplies, important dispatches which are more likely to be intercepted,scrambled and/or decoded if sent by radio, human beings, etc.

Another object is to be able to effect similar contacts at sea betweenpickup and delivery planes and submersible craft of projected types,capable of high speed surface travel: as, for instance, contacts betweensuch underseas craft and carrier-based feeder planes, and between suchplanes and any other waterborne craft of adequate sizes and/or speedsfor reciprocal duties. While I do not graphically show all of thedifferent carrier forms for which the invention is adapted, it will bobvious, after the full benefitto be derived from the presentdisclosures, that only mechanical skill and ordinary engineeringtechniques would be necessary to hereafter carry out the requiredadaptations, as circumstance may determine.

Other objects will be apparent from the detailed description hereafter,relative to the draw ings, wherein- Fig. 1 is a side-elevational view ofa transcontinental type of airliner, fitted with certain take-over anddelivery apparatus, including one well known existing type of lightpickup or feeder plane which may be employed cooperably therewith.

Fig. 2 is the partially laid open detail, in sideelevation, of arailborne transfer cab according to the invention, featuring certaininboard and outboard types of burden-transferring apparatus thereon andrelated thereto.

Fig. 3 shows one preferred kind of transfer hook which may be employedwith the feeder plane of Fig. 1, as viewed in side elevation, brokenopen to show a preferred mode of engagement of the same with certainboom tackle associated therewith.

Fig. 4 is also side-elevational, being the broken open detail of therailborne transfer cab of Fig. 2, for example, wherein other componentsof burdenhandling tackle are featured.

Fig. 5, in lineal perspective, is the fragmental view of a feeder planeof special type, showing how burden-transferring tackle thereon may beemployed with outboard tackle complementary thereto on either theairliner of Fig. 1 or the transfer cab of Figs. 2 and 4: in the latterview more specifically.

Fig. 6 is the detail of apparatus similar to that shown in Fig. 5,wherein a low-wing plane is depicted in front elevation.

Fig. 7 is a partially schematic, side elevational view (fragmental only)of apparatus wherein is featured burden-switching components slightlydiffering from those previously shown.

Fig. '7 is obviously a-human body, appendant from a duality of burdenlines, according to a technique applicable thereto.

Fig. 8 is a view of an airplane, in side elevation, havingburden-switching tackle comparable to that carried by the upper craft inFig. 1.

Fig. 9 is the plan detail of a boom suspension which may be employedwith the airplane of Fig. 8.

Fig. 10 is the side elevational representation of an aircraft engaged ina burden-switching operation with a high-speed submarine boat, accordingto the invention, and

Fig. 11 is a fragmentary plan view of the rear end of plane l of Fig. 1,partially broken open to further show the relative positioning of theelements there depicted,

Like reference characters in the drawings indicate parts of likestructure and like functions, unless otherwise specifically noted.

Referring to Fig. 1, the long ranging airliner l is there seen a briefmoment before contact has been made therewith by the light pickup plane2 for the purpose of snatching from said liner a burden, such as themail pouch or canister 3 or the burden 3*, depending upon which of afeatured two of the different possible arrangements and proceduresistobe adopted.

Plane 2 may also turn over a'burden (or burdens) to plane I, as morefully explained hereinafter. This latter operation, which isconveniently referred to as the burden delivery, may take place eitherbefore or after a pickup operation, conveniently called a burden snatch;and sinc it is desirable that these two distinct operations shall not beconfused, the pickup or snatch tackle proper and its uses will bedescribed first, relative to both of the preferred options previouslymentioned. For the further avoidance of possible confusion, however, itshould also be explained that certain elements of the burden-deliveringtackl may become components of the burden-receiving tackle andvice-versa, as beneficially employed. Moreover, both general classes oftackle are susceptible to variation, as will be made clear during aperusal of the following description.

Attention is directed initially to the burdenhandling apparatus of thepickup plane 2, with especial reference to its so-called snatch-tackle.Such tackle may include elements quite similar to certain facilitiesprovided as standard equipment on present types of pickup planes, suchas those flying the routes of All American Aviation, Inc., the pioneerin this field, i. e., except for specified changes and adjustments;which latter can be readily made in accord with the present disclosure.Or, alternatively, those features herein which constitute either broador specific improvements upon the prior art of burden-handling may beincorporated, by preference, into the modified structures. Hence theboom 4 of plane 2 may be strictly in accord with the drawings herewith,wherein superior results may be had therewith incorporating, to be sure,certain structural components already standard to the art as elements,only, in my improved devices-or changes may be made according to theparticular service demands, some of which are set out herein.

For example, it may be explained that while the structures which Idisclose and the techniques applicable thereto bear a recognizablesimilarly to comparable ground tackle, and to existent pickup tackle andmethods auxiliary thereto, the

comparison would, in other respects, be entirely inapropos. Thus boom 4is of a length usually deemed most desirable in relation to the size ofthe plane itself, with regard to such factors as the height of thepick-up standards commonly used at ground stations, the requiredclearance between the outboard end of the boom, whereon the pickup hookis secured, and the airplane landing wheels of the fixed outboard typeshown, the speed of the plane at the time of the pickup-usually in theneighborhood of 110 M. P. H.-and other considerations. In general, boomsof about 15 feet in length have been employed satisfactorily. And ifplane 2 is to be used in a dual capacity for both (1) picking upindividual burdens from a chain of ground stations and for thereafter(2) delivering these same burdens direct to the liner I, or a similarlyequipped but shorter ranging carrier, as well as for spot pickups anddeliveries over a return route, it is obviously advisable to provide aparticularly long boom; but not necessarily so unless the wheels 5,associated with the landing gear pants 6, are of this fixed outboardtype.

Thus, while the plane shown is of the general class inclusive of suchwell known light planes as the Stinson Reliant, etc., which class waspredominant when pickup services were inaugurated,

recent light plane types are of the low-wing de-' s'cription, havingfully retractingwheel gear, as exemplified by such light planes as theGlobe Swift. Because of the increased clearances afforded by retractablelanding gear, pickup booms could be shortened with regard, largely, topropeller clearances; and single nose-type propellers, also, can beplaced to increase lower clearances. (A further factor, as explainedhereafter, is the one which relates to replaceable pickup hooks, and tothe necessity for provision of means for replacing the hooks at theoutboard ends of the booms before each succeeding pickup or snatchoperation.)

If, however, and by option, one class of plane is to be employedexclusively for local pickup work, taking off at one terminal airportand eventually landing at another terminal airport, at which latterpoint the consolidated burdens are then to be transferred to aspecialand preferably faster-fiyingfeeder plane, whose primary functionis to take over and deliver said consolidated burdens to plane I inexchange for return loads, a much shorter boom may be used to advantageon the feeder plane. These distinctions, and the reasons therefor, willbecome more apparent after explanations have been given of certain othercomponents associated therewith.

Sundry types of boom suspensions have been devised, among which may beespecially mentioned the structure featured in Patent No. 2,373,413 toS. C. Plummer and the one shown in Patent No. 2,37 3,414 to saidPlummer, the former being particularly characterized as pivotallycarried adjacent the empennage whereby to return the outboard free endof the boom to aforwardly disposed hatch, which serves both as a burdenbay and as a means of ready access to said free end of the boom forrecurrent replacements of the snatch-hook. The latter named generaltype, on the other hand, is swingable from a pivotally mounted axle upforward, adjacent the plane's center of gravity and within the hatchway,the grapple or snatch-hook therefor (of specialized type) being readilyreplaceable just inboard of the plane, after each operation, forslidable movement through the hatch to the end of the boom along arearwardly placed track running longitudinally of said boom and adaptedto catch and hold the hook releasably at the booms outboard extremity.

For present explanatory purposes, it will be assumed that the latterdescribed general class of boom, but as herein substantially modified,is to be employed in the version featured in Fig.1. Thus, briefly, saidboom 4, Fig. 1, may have the Y-shaped yoke A adjacent its inboard end,as seen to best advantage in the enlarged views of Figs. 8 and 9; thetip-ends of the Y member being suitably welded or otherwise secured tothe aforesaid axle, identified conveniently as 4* in Fig. 9,substantially as shown. The axle 4 is carried at right and left inboardsides of a hatchway 45*, which latter is contiguous the pivot point Iwith the greatest area of the opening to the rear of the pivot. The boommay be operated in any serviceable manner, as by lever L, Fig. 8; and anautomatic winch drum 3, Figs. 1 and 8, may be employed in cooperationwith the burden-line 9. Line 9, however, is preferably connected to aspecial type of safety snatch-hook I0, whichwill now be explained fullywith reference to the detail of Fig. 3.

Hook I0 is seen to be telescopically, releasably,

. socketed within a suitable bore hole I l or the like of the lowershank I2 of boom 4, although, ob-

be socketed into said hook.)

vlously, variable other means, including less preferable alternatives,of releasably attaching the hook may be employed. (For one example, theboom could have a terminal or neck adapted to The preferred type ofengagement is made possible by providing the neck 13 of reduceddiameter, having, in this version, the recessed portion as shown forsnap-in action with the spring-latch element 14; the latter beingcomparable to one well known type of umbrella clip and suitably securedat its outer end portion to shank l2 as indicated. Thus when, and onlywhen, a pull is exerted directly longitudinally of the boom will hook Ibe freed readily from shank l2; thereby affording assurance against thepremature displacement of the hook from any other cause. Obviously, theposition at which the hook will be freely released from clip I4 is thatpredetermined angle which will be described immediately after loadtension is normally intially applied against the lower jaw of the hookat the cupped area i5, which can be readily determined and allowed for;it being understood that the boom will normally be automatically swungrearwardly under load, as will shortly be further explained. However,against the possibility of inexpert handling, producing a bind at theprecise instant when the hook should be quickly jerked from socket II,neck l3 may, if required, be quite short and clip l4 moved outward forcontact adjacent the shoulder of the hook where it abuts the end ofshank I2. Among other options, the neck portion I 3 could be a yieldablerubber plug or the like.

Consequently, according to well known techniques applicable to groundstation pickups,

wherein a cross-cord forming the taut area of a suspended ground-loop,so called, is contacted by book H], the hook will be freedinstantaneously as follows: First the loop-cord represented in schematicsection atit will be impinged against the lower shank of the boom,moving instantly to position I! and thence through the optionalspring-operated guard element l8 to said cupped area l5. substantiallyas shown. As indicated by phantom l 9 of the loop-line, the firsttension will be a quick backward and then a straight colongitudinal tugto release hook H]; and instantly thereafter, the drum line 9, havingbeen made taut by the initial weight of the burden thereon,

. will automatically cause the now freed hook to assume a position inwhich the loop-dine will have moved to the lower cupped area 20, asgraphically shown by phantom Ili The drumline '9, of course, in positiona will then exert a straight-on pull through the eye member 2| andthrough the jaw proper of the hook against the tension of the loop-linein position l9. Obviously, these positions are relative to the positionof hook ill before and thence after its release and will be variablydifferent at successive instantaneous stages of the pickup operation. Itis scarcely necessary to point out the special advantages of a hook soconfigured, for the express duties that are to be performed, since theyare quite self-evident. And it is also apparent that optional guard i8will usually be unnecessary, as premature escapement of the loop-linecannot ordinarily occur. Omission of guard 18 is particularly indicatedin services where rapid burden removals and hook replacements arenecessary, and wherein time (such as would be required for manipulatingthe guard) is at a premium.

The drum-line 9, which is preferably payed off from the aft side of drum8, located forward of the hatch, may be loosely clipped releasably tothe back of boom 4 at one or more widely spaced intervals. by suitablebreak-out fasteners 22, or these may be omitted and the line 9 permittedto freely flutter at position 9 when in the outboard nosition. Boom 4,in accord with the aforesaid patent of record, and in common with thelocation of the hatchway as well, may be positioned at one lower side ofthe fuselage; said boom being therefore mounted at a slight angle to theaxis of its pivot, enabling it to lie well within the longitudinalconfines of the fuselage when retracted. This feature is clearlydisclosed in Fig. 9. Specifically, boom 4, when folded, is desirablyadapted to be received into a longitudinal slot which conforms with thephantom 4 of Fig. 1, representing the boom in its inboard position. Andit is desirable, if hook I0 is to be employed, that the longitudinalboom-slot S, see Fig. 8, shall communicate, along its entire length,with the interior of the cabin C by means of a narrow opening, whichopening need be of a width only sufilcient to permit unimpeded exit ofthe drum-line 9 therethrough whenever the boom is extended. This isnecessary for the reason that after each burden has been taken inthrough the hatch, as more fully clarified hereafter, it is necessary toreposition hook 10 at the end of the boom; and on this account theaforesaid longitudinal slot is widened into an enlarged opening (notspecifically shown) at the area surrounding the hook, in its installedposition, permitting the required freedom of manual manipulationtherefill.

The relative inaccessibility of the boom-end, when employed with hookl0, wherein extremely long booms are indicated, may be obviated inseveral ways. For example, hook l0 may be retained on extra long booms,suitable for spot pickups at ground stations as well as for interimcooperation including deliverieswith airliner l, by following, asrequired, the general arrangement set out in said first mentioned PatentNo.

. 2,373,413 to S. C. Plummer. In short the boom may be pivoted in suchmanner that its free end can be readily swung forward into the hatchwayfor handy replacements of the hook. It is felt, however, that. thearrangement in Figs. 1, 8 and 9 is to be preferred, for reasons thatneed not be detailed here, and that, even in said general utilityservices, including surface pickups, a much shorter boom can be used bythe simple expedient of using low-wing planes with retractable mainlanding wheels. Thus, if plane 2 were of such a type, boom 4 need be nolonger than indicated approximately by the arcuate line 23, Fig. 1, andthe flight-line 23', making it possible for the flight mechanic to makehook-replacements quickly and With little difficulty. A still shorterboom, affording yet greater accessibility, will be entirely practicalfor the general utility pickups, as. will shortly be explained.

Wherein plane 2. is to be used in feeder duty only, however, to and fromliner I and not for general ground station work as well, and whereinretractable landing wheels are employed, it' is thought that aparticularly short boom to swing in the arc of curved line. 24, bringinghook ill to the flight path of line. 24', will sufiice. This would beparticularly true if, in a short time, propellers are. discarded, evenfrom relatively light aircraft, in favor of straight turbojet propulsionas. is predicted by eminent, engineers. For it should be well understoodthat in pickup and delivery duties of this character, which may beconveniently referred to as co-velocity service, each detail of theoperations may be performed with a degree of deliberation and accuracyimpossible in ordinary ground station work. That is, impossible wherethe burden is on a stationary support, on the ground for example, at thetime of pickup and wherein accuracy is dependent largely upon theprofessional skill of the pilot.

As for the shortening of boom 4 for handy hook replacements-even ifpants 6 and whee1 are retained and positioned as shown, while stillproviding a longer reach for utility pickups including ground-loopwork-this may readily be accomplished in accord with Fig. 9. Thus,without detailing all of the features shown therein, which are similarto those in said second patent to Plummer, it is obviously a matter ofsimple mechanics to so mount the axle 4* upon a rollable carriage,including Wheel members W directly below the respective pivot-points 1,that the entire wheel and boom suspension may be moved, in any preferredmanner, along a short trackway indicated generally by the rails R. andphantom position 3 of the Y-assembly. Consequently, where boom 4 isfirst retracted to its substantially horizontal attitude and is thenrollably swung forward to position 4 its hook in (not shown in Fig. 9)may be replaced approximately at location Ili as indicated by arrowpointer in Fig. 8; Whereas, when re-extended, said boom-hook will followthe outer arc I0 Therefore, by more preferably employing both theaforesaid rollable carriage and retractable landz'ng gear, a very shortboom may be used which can swing within the lesser arc I0 This would 0eof especial advantage in so-called co-velocity duties, according to theinvention. Flight lines F and F are self-explanatory.

The broken line i Fig. 8, indicates approximately the angle of swing ofthe boom 2- at which the schematic loop-cord it, having been initiallydisposed at position It? and having thence been struck by boom 4* atposition Ni will move instantly to location 15 (conformable with line 56at location 59 Fig. 3), inside the jaw of the hook H) and will jerk saidhook from the boom. Position 45 indicates the location of the loopcordjust an instant prior to the release of the hook.

Referring again to Fig. 1, it will be noted that airliner i is fittedwith a pair of extensible and retractable standards 25 on right and leftsides, respectively, of the fuselage near the tail gear; it beingassumed that the second of these is positioned directly behind thesingle standard 25 graphically shown. These standards have a utilitysomewhat comparable to that of ordinary ground station poles but aredesigned for coordinated speed service. Standards 25, in this preferredversion, are preferably pivotally mounted in any desirable manner forrapid extension to upright positions, as indicated by said singlestandard 25; and when inactive may be received into narrow recesses at26 on respective sides of the fuselage.

Recesses 26 are more clearly seen in the fragmentary and broken openplan view of Fig. 11, where the standards 25 are shown in theirretracted positions. Said recesses are obviously much enlarged forgreater clarity in the relatively small drawing. In practice, they wouldclosely and snugly receive the respective standards. When each of theseis elevated to the upright,

1Q position of standard 25 in Fig. 1, the line [9 of the burden 3 willoccupy the transversely stretched position I9, in the proper attitude tobe snatched by hook I!) of boom 4. The standards are here indicated tobe pivoted at respective locations 25. Obviously, the specifica-rrangement shown is subject to sundry modifications Which mayhereafter occur to skilled designers of the related art.

An advantage of the arrangement in Fig. 1 is that standards 25 may be ofa length and configuration such as to bring their tips into respectivepositions at the rear end of the fuselage, substantially as indicated,for handy attachments of the loop-lines, which latter are also normallyaffixed to the baggage to be transferred. Detailed provisions as to doorclosures, etc, are not graphically shown since such matters are alsowithin the domain of ordinary skills and the same can be readilysupplied in general accord with these disclosures.

Thus the burden 3, resting on any serviceable support, may have saidconventional loop l9 affixed thereto and releasably to standards 25,burden 3 merely being given a backward shove through the rear door D ofthe baggage room R as required, at the time of each pickup operation tobe detailed hereafter. Light burdens, once caught in the slipstream,will trail to a position at which they may thereafter be taken aboardplane 2 in the regular manner. If desired, however, a shorter loop maybe used, terminating in a single brief length of cordage attached to theburden and adapted to be carried over a sheavewheel similar to wheel 27on the'tow-cab of Fig. 2. to be described later. And an auxiliaryfeed-out line, so called, as also fully explained hereafter, may beemployed to facilitate such transfers especially wherein relativelyheavy burdens are to be handled.

According to another arrangement, standards 25 may be located forwardly,as, for example, a short distance from the fuselage at right and left ofsame and extensible from the upper wing surfaces, as indicated inphantom at position 25*. Standards 25 which are assumed to be in theusual duality, could retract inwardly to one another, so that their tipends could be readily recurrently fitted with the loops of eachsuccessive unit of baggage to be switched; this operation taking placejust inside the opening of an upper hatchway indicated generally atnumeral 28 it being understood that the wings of the liner I, in thisview, are slightly dihedral, and that the orthodox (or similar) type ofbreak-out clips'29 (see Ballard, No. 2,369,518), when the standards areretracted, may be on a. lower plane than the pivot-points 363. One suchan arrangement is clearly shown and detailed in my first aforesaidapplication, Intercooperative System for Airborne and Surface Carriers,where, in the end- View of Fig. 19 thereof, the tip ends of right andleft standards 12% come quite closely together at area 132: which seefor any required further clarification of like or similar features inrespect to Fig. l of the present application.

Standards 25, and similar pivoted standards herein, may be operated bytorsion springs (not shown) or in any other desired manner which willreadily occur to designers of the art. When not in use, hatch 28 may beclosed by suitable slidedoors or the like which are not thereingraphically shown.

It is quite apparent, of course, to those familiar with ordinary pickuptackle, that plane 2 in Fig. 1

is in the correct position to snatch the loop-line W from standards 25;and the same is true with respect'to said plane 2 in position 2*relative to standards 25 In the latter case, the burden 3 can be liftedup incline 3| through hatch 28, whereupon, on being caught in theslipstream, it Willunless quite heavytrail at position 3 until takenaboard of the ickup plane. The heavier burdens, as already intimated,may be dealt out on auxiliary feed-lines, to be again referred to later.7

While probably not required for these relatively easy coordinated speedpickups, it is possible, but more expensive, to control the aim of hookH3 in either position shown by electronic homing devices 32-33,cooperable with complementary seeker instrumentalities indicateddiagrammatically by element S on plane 2. The preferred positions forhomes 32 and 33, if used, will be too obvious to technicians of the artto require further comment thereon. Such devices may be very desirableif pickups are to be performed at night or under any other conditions oflow visibility. Likewise, a highly sensitive radar type altimeter (notshown) may be used, if not too expensive, to register the correct flightlevel of plane 2 relative to the upper skin of plane Flag beacons, ascommonly employed on ground station poles, are optional; as see saidpatent to Ballard, No. 2,369,518.

While I have initially described two options with relation to certainpickup tackle carried, respectively, by both liner and plane 2, it will,in all likelihood, be more advantageous to normally complete a fulldelivery operation from plane 2 to liner (to create more cargo roomaboard plane 2) before performing the pickup in the manner explained.And while final decisions can best be left to skilled specialists, it isapparent that deliveries from plane 2 could first be made at the rearend of plane 1, according to burdenreceiving tackle thereon to beexplained shortly; after which plane 2 can move forward for the returnpickup load at position 2*. And when burden 3 has been snatched throughhatch 28, plane 2 is then ready to bank and return to its subsequentduties, as predetermined. Of course, any plurality of successivetransfers may be made if necessary. Later, a somewhat simplified andperhaps preferred, method of successively and very rapidly interchangingburdens will be described with respect to Figs. 4, 5, 7, etc.

One practicable method of receiving a burden from plane 2 involves theuse of a boom of variant type, as shown in the phantom 34 (see also theboom 34 of Fig. 4), having the special safety release-hook 35 thereon.Details of boom 34 and book 35 are not here given, since they may be thesame as the boom and hook of similar configuration shown, and quitefully described in said first named co-pending application. In brief,however, it may be explained that the partially upstanding hook 35 isadapted to snatch a loop-line appendant from plane 2, connected to aburden inside the plane, an operation which will now be describedfurther in connection with the detail view of Fig. 5.

According to one arrangement, wherein a pickup and delivery plane isemployed of the fixed landing-wheel type, the legs are enclosed by pants6E, terminating in streamlined guards or gaiters 36-36. On the innerexternal sides of pants 66 are formed a complementary pair of grooves3'! adapted to receive the downwardly extensible standards 38-48,carried from respective pivots 39. A telescopic arrangement (not shown,since not preferred) is also possible, whereby the standards could movevertically on the planesof the pants. Any suitable mechanism may beemployed to simultaneously extend and retract standards 38. If desired,the tips of the standards may be curved as indicated by phantoms 40 soas to extend upward to and along the curvature of the lower fuselage,whereby to project through a small opening in said fuselage. In thisposition, the loop 4| may be readily secured to clips 42-42 whileretracted; and loop 4|, passing rearwardly above a narrow slot (notshown) on the underside of the fuselage, extending backward from saidsmall opening, may be connected to the eye 43 of burden 44 restingadjacent the opening to hatch 45, so, in its extended position, the loop4| may be aimed at boom 34 just below hook 35.

This can be accomplished, with a forwardly faced hook, by first movingthe plane 2 ahead of the hook and then falling back as required for theengagement. A window W of Plexiglas or the like may be provided underthe pilots seat to facilitate this operation. Upon contact, the loop 4|will slip backward into the jaw of the hook about the same instant thatbreak-out occurs from clips 42, at which time the standards 38 canretract in any preferred manner into the grooving 31. Obviously theburden will be snatched through hatch 45, and on retraction of boom 34to its recumbent position 34 Fig. 1, said burden will trail to the rearas indicated by the position of the loop 4| at M That is, if the burdenis comparatively light. Heavier burdens may call for the use of thepreviously mentioned auxiliary feed-out line, as will be described veryshortly.

A somewhat clearer view of this operation may be had by reference to thedetail of Fig. 4. While this exhibit relates to the aforesaid tow-cab ofa railborne vehicle, the burden-switching components are substantiallythe same as seen in Fig. 1, along with certain auxiliary tackle notshown therein but which may be similarly employed on liner Assuming,therefore, that boom 34 is the same as boom 34 of Fig. 1, it will, onengagement with loop 4|-which is thus schematically indicated in sectionat M -retract rearwardly to recumbent position 34 as also seen in Fig.1, with burden 44 trailing approximately as indicated at M It is now asimple matter for the flight mechanic, holding the small snap-hook 46,which is the terminal fixture on line 41 extending from drum 48, toengage this hook to one side of the loop portion of line 4|; whereupon,on jerking the pull-cord 49, according to like detailed means andprocedures explained fully in said first co-pending application, to openthe jaw of hook 35, position 35 line 4| will be freed from said hook andthe burden will immediately trail from the drumline 41 at the lower lineposition shown. It can now be quickly reeled aboard. Said detailed meansand procedures relative to pull-cord 49 are given in considerable detailin the copending application, wherein element 189 associated with hook139 of Figs. 14 and 15 is substantially identical with the likecomponent 49 of the instant application; only the configuration andvariant application of the respective hooks, per se, being different. Orsee the more directlycomparable pull-cord 1'76 in Fig. 20 of thatapplication, which operates in general accord with said previouslymentioned element 189 of said copending case.

Obviously, if the burden is quite small, the use of hook 46, line 41 anddrum 4 8 may be omitted, the flight mechanic merely pulling the burdeninward manually without troubling to free the loop-line from the hook atposition 35 until said burden is well inboard of the plane.

It may frequently-or usually-happen, however, that burdens of this classare quite heavy; and instead of trailing somewhat kitewise in theslipstream, they may sink through the same and prove difficult tocontrol and to haul aboard. I therefore provide, as auxiliary rigging,the feedoutline i), and wherein line 50 is used, a different techniqueis required. That is, line 55) is releasably connected to eye 43 of theburden while still inboard of plane 2 and the other end of this line isdesirably affixed to a small hand-operated reel (such as reel R aboardof said plane; eye 43, in this case, being sufficiently large toaccommodate both the terminal of loop-line 4i and the snap-on hook 5|(Fig. 4) at the outer end of line 50. Thus when the loop-line 4| issnatched by hook 3'5 and burden 44 slides downward through hatch 45, itwill not fall entirely by gravity but will be payed downward, throughthe hatch, at the end of said feed-out line.

At this juncture the flight mechanic inside the baggage room R willreach up and take hold of the loop-line 4 l, which is still held by hook35 at position 35 and will begin pulling down on same; so that theburden, being mainly supported by line 59, will be in an intermediaryposition, relative to the respective lines, which can ratherappropriately be called the attitude of a monkeyon-the-string. In thisattitude, the burden is pulled downward and somewhat inward toward therear doorway until the flight mechanic or an assistant can fastensnap-hook 45 to eye 43, as was earlier described in a somewhat similaroperation relative to loop 4| and as soon as the burden has been thusmade securely appendant from winch-drum 48, and thence drawn wellinboard, the flight mechanic normally unsnaps the terminal 5! of thefeed-out line and the latter may thereafter be reeled back through thehatchway of plane 2.

This technique, which may be found the pre ferred one for both mediumweight and heavy burdens, makes possible another major modification ofthe variable methods which may be employed. In brief, it makes possibleboth a burden pickup and a burden delivery as virtually one coincidentaland almost simultaneous operation. This is done very simply. Beforearrival of the plane 2, the flight mechanic on plane I singles out theburden to be transferred and places it upon any suitable convenientsupport adjacent the rear door, as at position 35*. Such a burden mayhave a very short loop-line 4t or line M may be a single strand, havingat its free end the snap-on terminal 52. (It would, of course, bepossible to even dispense with line 41 as will become apparent from thefollowing explanation.) And line 50, for such service, may, moreconveniently, be provided with an auxiliary terminal, such as thespur-ring 53. Hence-in accord with the procedure which was justpreviously described relative to a burden delivery by line 50as soon asthe burden at position 35 has been engaged by terminal 46 and is therebysafely appendant from drum 48, the flight mechanic quickly snaps book 52on ring 53, and unsnaps hook 5i to free line 50 from the incoming burdenwhile simultaneously exchanging this load for the burden resting atposition 35'. The latter can then be given a" shove through the doorway,if necessary, to provide the required clearance, while being reeled upto plane 2. The kinked back appearance of the loop-line at position 4P,incidentally, merely indicates the approximate doubling up of this linewhich will occur as the flight mechanic pulls inward and downwardthereon, as earlier explained. Still further refinements in feeder-linetechniques will be given later, relative to Figs. 7 and 7*, following anexplanation of certain additional features which pertain to precedingfigures of the drawing.

The burden-releasing or so-called delivery tackle of Fig. 5, obviously,conforms to the structure of pickup planes as now commonly employed-suchas plane 2. It is felt, however, for reasons previously set out herein,that low-wing planes of the Swift class, that is, having retract-' ablewheels, would be preferred to plane 2. Accordingly, in Fig. 6, I showanother particularly advantageous arrangement of the standards 38, hatch45, and burden 44, which is self-explanatory. It is to be noted,especially, that by this arrangement said standards are adapted toretract within two narrow slots, indicated generally at positions 31 -31and desirably faired to the wing surfaces-which can communicate directlyinto the hatch, as indicated, for successively rigging up the differentloop lines to the break-out clips of the standards. These slots may bein any positions conveniently to the front or the rear of the wheelpockets, for example, which same, on the Swift, are well forwardadjacent the leading edges.

Reverting again to Fig. 1, boom 34 therein, identified as being similarto booms 34 and 34 merely indicates how, by option, both pickups anddeliveries can be effected through the hatchway 28, according toprocedures earlier described; it being understood that the smallcircular figure 41 is the schematic representation of a loop-line, asviewed sectionally, in readiness to be engaged by the hook 35'.

The previously described operations relate to burden switching fromplane to plane, wherein one of the same is first stacked above anotherof the same. As intimated, however, various other so-called co-velocityor relative-speed engagements may be made, including burden switchesbetween airplanes and other types of carriers. t will be unprofitable tographically show and describe all of the possible applications butcertain others will be dealt with briefly. Thus, with relation again toFig. 4, which may be regarded as the detailed rear-end portion of eitherplane I of Fig. 1 or the tow-cab 55 of Fig. 2, nothing further need besaid as to deliveries thereto (from plane to rail carrier) other than byreference to the plane-to-plane techniques already set out herein. Thisalso includes the combination technique wherein both a pickup and adelivery may be effected coincidentally through the aid of line 50, etc.The individual pickup operation, too, may be substantially identicalwith that which was earlier detailed in respect to Fig. 1.

That is, the standards 25 (Fig. 2) are readily identified as beingsimilar to standards 25; and loop-line W also, may be identical withline IQ of Fig. 1. The relatively light burden B is similar to burden 3of said Fig. 1 view. Boom 4 is seen just prior to engagement of hook it!with the taut upper cross-cord of the loop (not seen in this sideelevation) and the phantom B repre-- sents the position of burden Bshortly after the" pickup, the hook l then being in the freedpositionI0, as shown, relative to line 9 and loopline l9". With regard to otherfeatures of tow-cab 65, inclusive of wheels 55, tow-strut 51, and rail58, the said first mentioned co-pending application may be consulted. Ifit is desired to maintain a two-way, cab-to-plane (or plane-to-plane forthat matter) control over burden B until after its delivery upwardly toplane 2, hypothetically, line 41 in conjunction with hook 46 may beemployed as feed-out tackle; and if so employed may also be providedwith the spur-ring 53, if desired, for returning another burden fromplane 2 to baggage room R On release of terminal 46 from burden B, line41 can of course be recovered from a trailing position to drum 48.Obviously this type of feed-out line arrangement could also be employedrelative to planes and 2, for better controlling the upward travel ofburdens, as well as wherein line 50 was employed for downwardlydelivered burdens.

As mentioned earlier, burden-switching is not necessarily limited torelations between a feeder type of light plane 2 in cooperation with cab55, for illustration, of a railborne vehicle, or with airliner i; andfor extra heavy duty work, wherein plane I may be operated to performsimilar duties in coaction with another large aircraft, it is possible,on planes of this size, to provide at least a duality of pickup booms 59and 6|] having suitable burden-hooks 6! and E2 thereon adapted tocooperate with respective hatches indicated generally at 63 and 64. Suchbooms could be swingable from pivot points 65 and 66.

With reference, now, to the detail of burdenswitching apparatus shown inFig. '7, it is to be noted that while most of the components in thisview are similar to those earlier described, especially in relation toFigs. 2, 4 and 5, this modification differs therefrom in certainparticulars. Boom 61, for instance, while operable similarly to booms34, 34 and 34, from a pivot 68, and adapted to retract to the recumbentposition 6! within an elongate groove 69, in a dosal position relativeto the carrier in (which may be the tail end of an airplane, a railbornetow-cab or similar device), or as modified in connection with hatch 2Bof Fig. l, is fitted with the detachable burdenhook Hook ll isrecognized as quite similar to hook I0 on the pickup boom 4 of plane 2,and is connected at eye 12 to a burden line 13 adapted to be payed offfrom reel 14, as schematically indicated. Boom 61 has the off-set shankportion 61', preferably, whereby to retract the hook through an openingat the aft end of groove 69, into the baggage room R so thatreplacements of the hook may be conveniently made by the flightmechanic. In general, burden switching with the tackle of Fig. '7 neednot be greatly unlike the technique previously explained relative toFigs. 2, 4 and 5. The variables, however, can best be described byexplaining one preferred technique which may be employed to advantage.

Assuming, therefore, that a burden is to be delivered to baggage room Rfrom a feeder plane, such as plane 2 which is here indicated merely bythe detail of burden-releasing means appendant therefrom in the form ofstandards 38 and the loop-line 4|. Assuming, also, as was previouslyexplained in respect to Fig. 5, that the burden to be delivered to roomR is the same as seen in said exhibit, that is, burden 44. Moreover, theburden, presumably, is connected to both line 4| and to the feed-outline 50. Obviously, then, when hook 1| (returning to Fig. '7)

impinges against the cross-cord of loop-line 4|, the initial result willbe to snatch the burden 44 (Fig. 5) from hatch 45 before boom 61 of Fig.'7, operating by slightly delayed action against the cushion afforded byshock-cylinder 54, has been retracted rearwardly tothe angle at whichhook ll will become automatically unsocketed. Thus said burden is firstseen in the Fig. 7 view at an upper position 44 appendant from both line4| at position 4| and line 50 at position 50 Immediately thereafter,however, with boom 61 having swung to recumbent position 61 the burdenwill be-fcr an exceedingly brief instant-at position 44 with line 50 at50 and the loopline at position 4| The moment that hook H is at thehorizontal and burden 44 has been payed out to cause said burden toexert a straight-on pull against said hook (which was assumed, in thiscase, to be burden position 44 the hook will be jerked from the boom, asat position H and burden 44 will now be trailing from reel 14 atposition 44 but still controlled from line 50 at location 50.

In order to facilitate the ready release of hook H from boom 61, anydesired additional length of line 13 may be payed off. It now onlyremains to complete the delivery by hauling the burden into room R. asrequired. That is, a light burden can be pulled in manually, but if theburden is heavy and the slipstream very strong, reel 14 is operated todraw it inboard to position 44 In view of the fact that hook H is not tobe desirably wound on reel '|4-and while other expedients could beadopted to free the hook from the loop-line, while retaining control ofsame-it may be found most expedient to mount reel 14 movably at position14 for example; so that, in order to bring the burden well into thebaggage room while hook continues to maintain line 4| is a tautrelation, it is merely necessary to move said movable reel backward toposition 14'; that is, along the path generally indicated by upper andlower broken lines l5, 15. Very heavy burdens can be hauled aboard inthis manner, employing any preferred means to move reel 14 from position14 to position 14 As explained earlier, the feed-out line 58, atposition 50 may be quickly unsnapped from the burden and reeled back toplane 2. Or the burden in waiting 16, having the short length of line 11connected thereto, inclusive of snap-hook 78, may be quickly attached tothe spurring 19 before releasing the connection 5| on the receivedburden, whereby to exchange burden 16 for burden 44. Needless to say,any reasonable additional rings l9 could be provided on line 50, if itis desired to attach a small cluster of burdens thereto at spacedintervals; or all could be attached to a single ring if of suitabledimensioning. Furthermore, in order to maintain the maximum of controlover exchange burden 16 while passing through the slipstreams of bothcarriers, I also provide the lower feed-out line 80, which pays off fromreel 8|; line being normally connected as indicated to burden 16 beforehook 18 is snapped on ring 19. Obviously, line 80 will be payed out onlyas required while burden 16, under two-way control, is being firstelevated and then reeled aboard plane 2; and will thereafter, upon itsdisconnection aboard plane 2, be retracted to reel 8|.

While the various burden-switching operations have been described withreference to inanimate mail or baggage, it is obviouslypossible-especially in time of emergency, and in the course of 17military operations-to transfer human beings quite safely in a similarway.

Such an operation is briefly illustrated in Fig. 7 utilizin bothdrum-line it or the like (see Fig. 7) or just a loop-line ii if boom 34is employed instead of boom 6?, as well as a feed-out line era. Thehuman body t l is presumed to have descended from an upper aircraft Aand is about to be received into a lower aircraft A substantially asindicated. To carry out such an operation, however, it is desirable toprovide a suitable harness 82; and since individuals who are to beswitched in this manner will probably be equipped also with parachutes,such as the back pack 83, for illustration, it is readily possible toprovide any preferred additional strap thereon, such as element 84,having a metal thimble or the like, to which line 50 may be securelyconnected releasably.

By option, in the cold upper air, the man 8! may have his wristsmanacled together by any suitable device adapted for connection to theloopline M at eye 85, whereby to insure a properly trussed positionthroughout the transfer, without imposing undue strain upon arms andhands or relying upon a mere palm grip for security; line 4| beingadditionally connected to a chest plate P or the like as indicated. Orany other preferred means for attaching line 58 and/or line ll may beutilized. The man in Fig. 7 is wearing a special airmans suit, as wellas a helmet, with goggles, for protection against the action of theairstream. Wounded men, obvicusly could be similarly switched accordingto minor variations in the technique herein disclosed, and which will,hereafter, readily occur to slzilled operators of the art.

A final word, at this point, in further reference to the apparatus ofFig. 8;

Wherein the airplane 2 is to be used not only for airborne transfers butalso for spot deliveries and pickup as well, over local ground routes-orwherein restricted to such latter servicesit may be desirable to includedrop-off tackle on the aircraft: that is, means for delivering burdensat particular ground stations from a height quite close to the ground;it being a normal procedure for present airplanes of the comparable typereferred to to deliver one or more burdens just prior to picking upanother burden at such points. For this purpose, therefore, I alsoprovide that plane 2 may have a second hatchway, indicated generally atnumeral 90, as well as another reel 95, including the delivery line 92payable therefrom. Line 92 bears the delivery hook 93, substantially asindicated, which hook can be quickly connected to the burden to bedropped a l, as, for one possible arrangement, by means of the shortloop 95. Since hook 953 is adapted to instantaneously free burden 94upon actuation by the flight mechanic, it is provided that this hook maybe of substantially the same type as the earlier mentioned hook of Fig.14 in said copending application Intercooperative System for Airborneand Surface Carriers, but carried at the end of a suitably small shank86; whereby, on application of sudden sharp manual tension upon theauxiliary pull cord 9'4, the jaw of the hook will immediately yield tothe tug of the burden 9d and thus free loop 95 and the burden connectedthereto.

In short, both the very short line 92 and the short pull-cord ill can bewound together on the same reel (reel 9 i) and it is a simple matter forthe flight mechanic to take hold of the pull cord,

only, when ready to jerk the same sharply at the instant the burden isto be dropped. As burden 94 may be trailing quite close to the ground atthe time of delivery, mail sacks and the like can be dropped with aminimum of injury to either the container or its contents. Obviously,upon release of burden 9 line 92, inclusive of cord 97 and hook 93, maybe quickly retrieved through hatch 95 without interferin with theoperation of the complementary picku tackle.

The components of Fig. 10 are self-explanatory, including the highspeedsubmarine S36 and feeder plane 2, the water craft being fitted with acab ill burden-receiving apparatus inclusive of boom 88, as well as afull complement of other burden-switching facilities, such as describedrelative to Figs. 2 and 4 or Fig. 7. Among these facilities are thestandards 89; and it is apparent, in view of the technique earlierexplained relative to Figs. 4 and 7, that burdens may be switched eitherfrom plane to submarine or from submarine to plane.

Having merely explained certain particular physical embodiments by meansof which the invention may be carried out, and certain preferred methodsapplicable thereto, it will be understood that my concept is in no waylimited by, or solely to, these embodiments or these methods. Theinvention, in short, is to be limited only to a proper interpretation ofthe hereafter appended claims.

I, therefore, claim:

1. In a burden-sv-ritching system, the combina-- tion including: a firstmobile body; a second mobile body; a burden on each of the bodies to beswitched therefrom to the other thereof while bodies are traveling atcoordinated speeds, of said bodies having a hatchway through whichburdens are transferred; outboard means on an upper of said bodies, towhich is releasably attached one sectional portion of a burden line,another portion of this line being connected to the burden on said upperbody; a line-engaging means extensible upwardly from the lower of saidbodies for releasing contact with said first sectional portion of saidburden line; an auxiliary feed-out line, bearing means by which one portion thereof is also connected to said burden on said uppermost body;line pay-out means on said upper body, to which another portion of saidauxiliary line is connected, and from which it is progressivelyextensible, in burden-supportingand-controlling relations, while saidupper burden, upon its transposal normally through the hatchway in saidupper of the bodies-- incidental to the contact of said line-engagingmeans with the outboard portion of said first burden line and thelatters entire relinquishment, along with said upper burden, to saidlower of the bodies-is being normally hauled inboard the lower of thebodies through its own burdenreceiving hatchway; the burden on saidlower of the bodies bearing means by which it, in turn, is connectableto said auxiliary line for transference through the air to said upper ofthe bodies.

2. In a burden-switching system, the combination including: a firstmobile body; a second mobile body; a burden on each of the bodies to beswitched therefrom to the other thereof while said bodies are travelingat coordinated speeds, each of said bodies having a hatchway throughwhich burdens are transferred; outboard means on a lower of said bodies,to which is releasably attached one sectional portion of a burden line,another portion of this line being connected to the burden on said lowerof the bodies; a line.- engaging means extensible. downwardly from theupper of said bodies for releasing contact with said first sectionalportion of said burden line; an auxiliary feed-out line, bearing meansby which one portion thereof is also detachably connected to said burdenon said lowermost body; line pay-out means on said lower body, to whichanother portion of said auxiliary line is connected, and from which itis progressively extensible, in burden-supporting-and-controllingrelations, while the said lower burden, upon its transposal normallythrough the hatchway in said lower of the bodies--incidental to thecontact of said line-engaging means with the outboard portion of saidfirst burden line and the latters entire relinquishment, along with saidlower burden, to said upper of the bodiesis being normally hauledinboard the upper of the bodies through its own burden-receivinghatchway; the burden on said upper of the bodies bearing means by whichit, in turn, is connectable to said auxiliary line for its transferencethrough the air to and into said lower of the bodies.

3. A burden-switching system which includes, in combination: a first anda second mobile body traveling at coordinated speeds with respect to oneanother and adjacent one another, at least an upper of said bodies beingan aircraft; a burden on one of said bodies to be transferred throughthe air to and into the other thereof; flexible line tackle connected atone portion thereof to said burden; outboard line-supporting means onthe burden-bearing body, from which another portion of said line tackleis releasably supported; line-engaging means extensible from the otherof said bodies and operable to make releasing contact with said anotherportion of said line tackle, for establishing a first burdentransferringcontact between the respective bodies; an opening in said upper of thebodies, and another openingin the lower thereof through which burdensare transferred; an auxiliary burden feed-out line connected, at oneportion thereof, to said burden; and means, associated with the otherend portion of said feed-out line, operable to pay-out progressiveportions of this latter named line coincidental to the normal passage ofsaid burden through the opening of the burden-relinquishing body, andits transference thence through the opening on the burden-receivingbody, responsive to the action of said line-engaging means and thecoincidental release of said another portion of said first flexible linetackle.

4. The method of transferring a burden from one airborne craft toanother which includes: flying a first of said aircraft above the otherat coordinated speeds therebetween; attaching one portion of a flexibleburden line to said burden, resting on the upper of the aircraft, andanother portion thereof, remote from said burdenattached portion, toline-supporting means therefor on said upper craft; attaching anauxiliary feed-out line to said burden; operating means on the lower ofthe, aircraft to releasingly en.- gage said another portion. of saidburden line,' for the establishment of a. burden-transferring.

contact between the respective crafts; and the relinquishment of theburden from said upper to said lower of the. aircrafts and its movementthrough the. air from one to the other while at least partiallystabilized-aeainst aerodynamic forces tending to force it. out ofcontrol-by the reiinquishment. of progressive portions of: Said.feed-out line from said upper of. the cooperatingaircraft.

5.. The augmented method of claim 4 which includes, as additional steps,receiving said burden on said lower aircraft, disconnecting saidfeed-out line. therefrom, connecting said feed-out line to a burden onsaid lower craft for its transference therefrom to said upper craft, andthe relinquishment of the latter named burden from said lower to saidupper of the respective aircraft.

6.. They augmented. method of claim 4 which includes, as additionalsteps, receiving said burden on said lower aircraft, disconnecting saidfeed-out line therefrom, connecting said feedout line to a burden onsaid lower craft for its transference therefrom to said upper craft,connecting another feed-out line to the latter named burden while stillaboard the lower aircraft, operating means aboard the upper aircraft tohaul in progressive portions of said first feed-out line, thecoincidental pay-out of the second-named feed-out line to the burdenfrom said lower craft, and its-said latter burdenstransference throughthe air from said lower to said upper of the respective aircrafts.

7. The method of transferring a burden from one mobile body toanother-at least an upper of which bodies is an air-borne craft-whiletraveling at coordinated speeds; said method including the disposal ofone terminal portion of a burden line between a duality of spaced,outboard line-engaging-and-releasing means on said craft; operatingmeans extensible from the lower of said bodies to engage said terminalportion of said line, and its release thereto from said firstline-engaging-and-releasing means; the further operation of saidextensible means to bring said terminal portion of said line to theproximity of a burden on the lower of said bodies tobe transferred tothe upper thereof; connecting said burden to said line, and itscoincidental disconnection from said extensible means; thence theretrieval of said terminal portion of said burden-line to, and entirelyinto, said aircraft, including the coincidental relinquishment andtransportation of said burden from said lower to the upper of the mobilebodies.

8. The augmented method of claim 7 which includes: connecting a feed-outline to said burden before its relinquishment from the lower of saidbodies, paying out progressive portions of said feed-out line to theburden during its transference to and into said aircraft, and, thence,the disconnection of the feed-out line from said burden and theretrieval of the payed out portion thereof aboard said lower of themobile bodies.

9. In combination: an aircraft; a burden thereon to be transferredtherefrom through the air to another mobile body; a first burdenlinewhich has initially been made fast at one terminal thereof. to saidburden and operable to establish a first burden-transferring connectiondirectly between the burden proper and said another body; and anauxiliary burden feed-out line, which also is connected securely to saidburden and operable to lower it from said aircraft to said other bodyfollowing the arrival normally of one end section of said first namedline, remote from said referred to terminal thereof, aboard said anothermobile body and the hauling down of this line against the tension ofsaid auxiliary line during said. lowering, procedure.

10. In an aircraft, the combination including: a fuselage having anopening formed in the lower side thereof; a rollable carriage devicemounted within the interior of said fuselage, on the floor side thereofforwardly of said opening; and a burden boom integrally attached to saidcarriage; said boom having a freely disposable rear end section thereof,to which a snatch hook is connected, and adapted forextensible-retractive movements, respectively, relative to said openingand to the aircraft underside responsive to normal forward and backwardmotions of said carriage.

11. As a new aeronautical combination, components including: aburden-relinquishing aircraft; a burden-receiving aircraft traveling aflight course adjacent the path of travel of said first mentioned craftand at coordinated speeds therewith; a human burden in process of beingtransferred through the air from said relinquishing to said receivingaircraft; a transfer harness secured to said burden, said harnesscomprising a main body-supporting portion thereof, means thereon towhich a first burden line is connectable at a location to facilitate thelowering of the burden downwardly from said relinquishing craft, and asecond line-engageable device to which a second burden line isextensible between said burden and the receiving aircraft; saidcombination including burden lines having terminals connected to therespectively named line-engaging means of said harness, one such lineinterconnecting the occupied harness with said relinquishing craft andthe other interconnecting it with said receiving aircraft, the dualitythereof being entrained in such manner that the burden itself occupiesan intermediary position between said lines for the duration of thetransfer operation.

References Cited in the file of this patent UNITED STATES PATENTS-Number Name Date 1,070,197 Snell Aug. 12, 1913 1,146,695 Dugro July 13,1915 1,439,927 Uppercu Dec. 26, 1922 1,474,457 Weinberg et a1 Nov. 20,1923 1,582,090 Smith Apr. 27, 1926 1,760,684 Clifford May 27, 19301,912,722 Perkins June 6, 1933 1,925,555 Bradshaw Sept. 5, 19331,973,244 Adams Sept. 11, 1934 1,992,300 Adams Feb. 26, 1935 2,102,604Arndt Dec. 21, 1937 2,131,610 Arndt Sept. 27, 1938 2,193,312 Cobham Mar.12, 1940 2,319,881 Ray May 25, 1943 2,373,413 Plummer Apr. 10, 19452,386,395 Hart Oct. 9, 1945 2,418,702 Du Pont Apr. 8,1947 2,433,437Cotton Dec. 30, 1947 2,433,473 Mitchell Dec. 30, 1947 2,437,619 SetzMar. 9, 1948 2,438,538 Hoehn et a1 Nov. 22, 1949 FOREIGN PATENTS NumberCountry Date 649,884 France Sept. 10, 1928 369,228 Great Britain Mar.16, 1932

